Sticky button problem

I have kids. They get crap on my controllers. My other console's don't usually have problem but for some reason my PS3 controllers get sticky buttons. I depress the buttons and they stick for a second. The ones that do this the worst are the shoulder buttons. I have 4 controllers. One became completely unusable, another is annoying, a third is functional, and one is perfect (it's the newest). Anyone else have these problems and have a suggestion for a fix? Why does this only happen to the PS3 controllers? Are the buttons too shallow into the base of the controller or something?

Do you guys have any experience with the PS3 controllers with the analog stick positioned like the 360 controllers? I've been thinking about getting one of those lately. Maybe it's because I switch between consoles and my left thumb muscle has become weaker...BUT my thumb HURTS after playing for a few hours. I compared the controllers and I think I like the 360 layout because when my left thumb is relaxed it moved upwards and and that's where the stick is. With the PS3, I have to stretch my left thumb far to the right the whole time since that thumb mostly stays right there.

So, anyone have those controllers with the 360 layout and have opinions of them? I started reading reviews and most of them seem to have people complaining about dead zones.

I figure since my controllers are getting sticky, this is a good chance to try out one of these. Opinions on them?

My controller does that sum times when im playing Dynasty Warriors because of pressing the same button alot, im still using the same controller that i've had for years when the button gets jamed i keep tapping it.